If you are dosing correctly like i said then there is no reason that your plants should be going brown... Especially as they're all low demanding plants that are easy to get along with. The Green Low product will be pretty much the same as any other basic fertiliser you buy. (unless it's a complete fert like TPN+)
As mentioned, get some pics up and we should be able to help you out. It may simply be that you're not dosing enough. You have to adjust it to what you think. I am now dosing roughly 8ml a day which has increased from around 2.8ml.
Remove the Vallis and Elodea. Remove any brown/yellow/see through leaves from the Vallis and replant. Prune the Elodea to the bottom of the greenery and replant. The moss isn't going brown, it looks like detritus from your tank that has got caught up in it. Mine gets it when i do filter maintenance as it blasts any loose mulm out into the water. The moss will grow through it.![]()